Cleaners[]
Zanka's relationship with the Cleaners is one of deep loyalty and belonging. Having abandoned his previous life, Zanka joined the Cleaners to grow stronger. He is a valued and trusted member, particularly within his team, where he is respected for his skills and strength as a powerful "Giver." His bond with the other Cleaners is built on shared experiences and a mutual understanding of their roles in the world. Unlike the rigid, hierarchical structure of the Hell Guard, the Cleaners operate more like a found family, and Zanka's journey to overcome his insecurities is greatly supported by the camaraderie he finds within their ranks.
Enjin[]
Zanka has great admiration for Enjin for helping him out in the past, which is what inspired him to quit training to be a Hell Guard and to be a Cleaner instead. Zanka works hard to receive Enjin’s praise, often very happy he does so, and holds Enjin in high regard at all times. Others noted that Zanka is rather soft with matters concerning Enjin, being labelled as a "pushover", but Zanka get annoyed at Enjin's teasing sometimes. They have a close mentor-student, brotherly bond as Enjin sees great potential in Zanka and understands his personality very well. Furthermore, they speak to each other as equals, especially when discussing important matters.
Rudo Surebrec[]
Zanka's relationship with Rudo begins as that of a mentor and a trainee, with Zanka being appointed as Rudo's trainer by Enjin. However, their initial interactions are fraught with tension and a feeling that they just don't click. Their first fight only confirms this, and a subsequent incident further complicates their dynamic. Despite this rocky start, Zanka fulfills his role as a mentor by eventually figuring out the conditions under which Rudo's Vital Instrument could appear, which is a key turning point in Rudo's development. As the story progresses, their relationship seems to be improving, suggesting they are getting closer and that the initial friction is giving way to a more positive and collaborative bond.
Riyo Reaper[]
As members of Team Akuta, Riyo and Zanka are gets along very well and usually act casual when interacting. They often help each other out in missions. However, Riyo's playful nature and tendency to tease everyone makes Zanka think of her as immature. Zanka does seem to care about Riyo though as he became distressed after she was nearly killed due to Amo’s powers in Penta.
Follo Tunito[]
Back at the North Ward, Follo directly watched Zanka defeat the moose Trash Beast right outside the crowded window. Zanka's actions gave Follo an idea, and he went up to Enjin, Gris, and Zanka to ask if he could be apart of the Cleaners.
Tamsy Caines[]
Zanka and Tamsy are seen working decently together during The Lady of Penta Arc. When Tamsy started to seem reckless with his abilities, Zanka shouted at him, confused at his actions. Eventually, they are able to successfully contain the rest of the Cleaners together.
Hell Guard[]
Zanka's relationship with the Hell Guard is one of strained history and profound personal conflict. Born into the prestigious Nijiku family, Zanka was originally trained to join the Hell Guard, like the rest of his family. Zanka did initially at the academy, but Zanka's sense of inferiority towards his rival Hyo and meeting Enjin led him join the Cleaners. This a move that created a significant rift between him and his family, which caused him be exiled. The Hell Guard's general distrust of "Givers" — individuals who rely on special instruments for power — puts them in direct opposition to Zanka's identity as a powerful Giver and a Cleaner.
Kyouka Nijiku and Goka Nijiku[]
Zanka and his elder siblings have a complicated relationship and are estranged terms with each other. In the past, Kyouka trained Zanka and put his through many tough training methods, such as teaching him how to dodge bullets. His family has high expectations for him and even Goka seems to feel some inferiority towards Zanka, who he viewed having greater talent than him. Kyouka encouraged Goka not to compared himself to Zanka since he isn't flawless and still young, and look after their younger brother as he needs to be protected. When Zanka choose to joined the Cleaners instead of being Hell Guard, Zanka was disinherited by the family. Both Kyouka and Goka are disappointed that Zanka chose a different path from them and failing to live up to the family's expectations. According Zanka, Kyouka was very upset at him when he decided to become a Cleaner because of her dislike of Givers.
Zanka has avoided Kyouka and Goka since then, as he became afraid and nervous to be in close proximity with either of them. Likewise, Kyouka and Goka refused to see Zanka during their visit to Cleaners Headquarters. Upon seeing each other at the Doll Festival, Zanka initially try to hide from Goka. While confronting Mymo, Goka behaves coldly Zanka and criticize his brother for being too dependent on his Vital Instrument. Despite not showing it, Goka still cares for Zanka in his own way, carrying him away from the battle when Zanka sustain a heavy injury and displays anger when Mymo purposely target him just to spite Goka.
Hyo[]
During their time as Hell Guard trainees, Zanka viewed Hyo as rival, who bested him in a combat session. Due to Zanka's pride, this served a crushing blow to his self-esteem and Hyo also called him out Zanka's desire for people sees him as a "genius". After meeting Enjin for the first time, Zanka has became more humble, but still aims to surpass Hyo ad getting stronger than her.
Raiders[]
Zanka's relationship with the Raiders is a direct opposition and conflict. As a Cleaner, his role is to fight against groups that cause chaos and destruction, and the Raiders are their primary rivals. During the "Raiders Trap Arc," Zanka demonstrates his exceptional combat skills and intelligence in a decisive battle against them. He proves to be a formidable opponent, utilizing his mastery of his vital instrument to counter their tactics, even when they attempt to use a numbers advantage and a mud-based strategy to gain the upper hand. In this fight, he not only defeats them but also showcases his ability to quickly adapt and overcome what appears to be an impossible situation.
Jabber Wonger[]
Zanka's relationship with Jabber Wonger is primarily one of conflict and rivalry. Jabber is a formidable enemy, and the two have a history of fighting. Viewing Jabber as another "genius" and having lost fighting to him before, Zanka is determined to get stronger and face Jabber again.